Production of low pour point gas oil and high octane number gasoline

ABSTRACT

A process for the simultaneous dewaxing of high pour point gas oil and upgrading of an aromatic containing naphtha by contact of a mixture of the gas oil and naphtha with hydrogen and a high silica to alumina ratio synthetic aluminosilicate zeolite catalyst, which is derived from a zeolite which was synthesized with an organic cation, at about 500* to 1000*F followed by distillation of the product in order to recover a lower pour point gas oil fraction and a higher octane gasoline fraction.

United States Patent 91 Garwood et al.

[451 July 15, 1975 [75] Inventors: William E. Garwood, l-laddonfield,

N.J.; John J. Wise, Media, Pa.

[73] Assignee: Mobil Oil Corporation, New York,

22 Filed: Aug. 24, 1973 211 Appl. No.: 391,380

[52] US. Cl. 208/111; 208/135; 208/141; 260/671 R [51] Int. Cl. C10G 13/02; CO7C 3/52 [58] Field of Search 208/111, 15, 102; 260/671 R [56] References Cited UNITED STATES PATENTS 3,516,925 6/1970 Lawrance et al. 208/111 3,597,493 8/1971 Frilctte et al. 260/666 3,663,430 5/1972 Morris 208/111 3,700,585 10/1972 Chen et a1. 208/111 3,729,409 4/1973 Chen 208/135 3,753,891 8/1973 Graven et a1... 208/62 3,758,402 9/1973 Oleck et al. 208/1 1 1 3,767,568 lO/l973 Chen 208/134 3,804,746 4/1974 Chu 208/111 3,832,449 8/1974 Rosinski et al. 423/328 Primary Examiner Delbert E. Gantz Assistant ExaminerG. E. Schmitkons Attorney, Agent, or FirmChar1es A. l-luggett; Michael G. Gilman [5 7] ABSTRACT A process for the simultaneous dewaxing of high pour point gas oil and upgrading of an aromatic containing naphtha by contact, of a mixture of the gas oil and naphtha with hydrogenand a high silica to alumina ratio synthetic aluminosilicate zeolite catalyst, which is derived from a zeolite which was synthesized with an organic cation, at about 500 to 1000F followed by distillation of the product in order to recover a lower pour point gas oil fraction and a higher octane gasoline fraction.

9 Claims, No Drawings 1 PRODUOTEON OF LOW POUR POINT GAS OIL AND HIGH OCTANE NUMBER GASOLINE This invention relates to petroleum processing. it

more particularly refers to the upgrading of various petroleum fractions.

Light gas oil, particularly the 330F and heavier fractions find particular use as jet fuel, Diesel fuel and home heating oil. 1n at least some locations, there is a specification with respect to maximum pour point (temperature) of these distillate fuels which many light gas oils cannot meet. As a result, the gas oil is down graded to lower value use such as residual fuel.

There has recently been developed a process referred to as catalytic hydrodewaxing in which the gas oil is contacted with hydrogen and a shape selective catalyst adapted to selectively crack or hydrocrack the paraffinic molecules in the gas oil. Initially the catalysts used were those zeolite cracking catalysts which had pore openings sized so that they would admit and crack only normal paraffins and exclude all other gas oil components e.g. erionite type zeolite. Later this process was improved through substituting ZSM5 type of zeolite for the previously used erionite type cracking catalyst. (See U.S. Pat. No. 3,700,585). Using this type catalyst permitted more efficient operation. In addition to the normal paraffins, paraffins with slight branching e.g. with a methyl side group, were also cracked whereby dewaxing was carried out to a greater extent. This permitted lowering of the gas oil pour point in a very efficient manner. The product of hydrodewaxing gas oil is suitably fractionated to produce high yields of dewaxed gas oil boiling in the same range as the feed, some naphtha and some light (Cf) ends.

There is a recently discovered process whereby naphtha containing aromatics, particularly reformate, can be upgraded from an octane point of view. This process contacts reformate with a ZSM5 type of zeolite at about 500 to 1,000F and space velocities of up to about WHSV whereby some of the normal and singly branched (methyl branched) paraffms are cracked to provide relatively small fragments which alkylate ar omatic rings present in the reformate feed. This converts very low octane material, i.e. paraffins, to high octane material, aromatics, byalkylation. Efficiencies in this process are rather high with excellent yields. (See U.S. Pat. No. 3,729,409). The product by this process is fractionated to recover high yields of higher octane naphtha as well as some light ends.

The catalyst referred to herein is inclusive ofa family of high silica to alumina ratio crystalline aluminosilicate molecular sieve zeolites having an organic cation as produced. These zeolites are known to catalyze the hydrodewaxing of gas oils by inducing hydrocracking of waxy components. They are also known to catalyze the upgrading of aromatic gasoline by causing cracking of low octane components and alkylation of the fragments onto existing aromatics. Exemplary members of the zeolite family useful in this invention are ZSM5 (U.S. Pat. No 3,702,886), ZSM-ll (U.S. Pat. No. 3.709979 ZSMl 2 (West German Offenlagenschrifft 2,213,109 and U.S. Pat. No. 3,832,449), ZSM21 (U.S. application Ser. No. 358,192 filed May 7, 1973), TEA mordenite (U.S. application Ser. No. 130,422 filed Apr. 1 1, 1971 and other similarly behaving materials.

1t is an object of this invention to provide a novel process for carrying out catalytic hydrodewaxing and reformate upgrading in a more efficient manner.

, ing a gasoline boiling range petroleum fraction such as naphtha or reformate containing at least about 20 weight percent aromatics and gas oil having a pour point of at least about +20F into a feed having a cumulative boiling range in the range of about C to 850F or any part thereof; contacting such feed with an organic cation derived, high silica to alumina ratio, crystalline aluminosilicate zeolite at a temperature of about 500 to 1,000F, a space velocity of about 0.5 to 20, a pressure of about 1 to atmospheres, and a hydrogen to hydrocarbon ratio of about 1 to 20 to 1; and resolving the product thus formed into a gasoline boiling range (e.g. C to about 400F) fraction having a higher octane number than the corresponding boiling range fed, a gas oil fraction having a boiling range higher than said gasoline (eg about 400F+) and having a lower pour point than the gas oil fed, and a minor Cf light gas fraction.

Exemplary of the catalysts which are useful for this process and which fall within the scope expressed hereinabove are ZSM5 type zeolites, ZSM-l2, ZSM21 and TEA mordenite. ZSMl 2 is described in West German Offenlagenschrifft 2,213,109 and U.S. Pat. No. 3,832,449; ZSMZl is described in U.S. Pat. application Ser. No. 358,192 filed May 7, 1973. TEA mordenite is described in U.S. Pat. application Ser. No. 130,442, filed Apr. 11, 1971. All of these references are incorporated herein by reference.

It has been stated, as a step in the described process, that a gasoline boiling range fraction and a gas oil fraction are mixed as a first step. Since most virgin gasoline fractions do not have sufficient aromatics content to meet the minimum specified herein, this admixture step contemplates a prior refinery operation, such as reforming, in which the aromatics concentration is increased followed by admixture with gas oil. It is to be understood, however, that a separate admixing step is not per se an absolute requirement of this process. It is contemplated that a petroleum cut encompassing both naphtha and gas oil boiling range materials can be taken from appropriate crude sources containing the required minimum aromatics proportion in the gasoline boiling range fraction and this wide cut fraction processed as further set forth herein. The mixing step should be considered as a requirement that mixed gasoline and gas oil be processed but not necessarily that separate fractions thereof be separately mixed.

it is surprising that naphtha upgrading and gas oil catalytic hydrodewaxing can be carried out simultaneously since each process was designed and intended to operate on a significantly different fraction of petroleum. In addition to the significant processing advantage in the single product resolution step for both the upgraded naphtha and the dewaxed gas oil, which results in major cost savings, this process has been found to result in higher gasoline yields and higher gas oil yields at the expense of light gas than were possible under equivalent conditions operating the two processes individually. This is so even if the processes are separately operated and their products combined for a single product resolution operation.

The catalyst can be used in a fixed, moving or fluidized bed as desired with the reaction zone appropriately designed therefor. The reaction zone may be operated in an upflow or downflow manner utilizing either trickle or flooded operation. The catalyst can be used as such or can be employed in a matrix as per the referred to patents and applications. It is preferred to provide a hydrogenation/dehydrogenation component, such as nickel or other metals having such known activity, in combination with the zeolite catalyst. In addition, the catalyst may be sulfided in known manner.

The zeolite catalyst of this invention should have a silica to alumina ratio of at least about 12 to l, preferably at least about 60 to 1. It may be used alone or in admixture with a matrixing material such as alumina or silica or the like. When used in a matrix, the proportion of active zeolite material is preferably at least about weight percent.

It should be noted that invention is not here claimed in any single or group of catalysts per se, nor in either the hydrodewaxing or the gasoline upgraded processes individually. Rather, invention is here claimed in the combination process described particularly with respect to its unexpectedly improved yield results.

This invention will be illustrated by the following Ex amples which are not to be considered to be limiting on the scope hereof. Parts and percentages are by weight unless expressly stated to be to the contrary.

EXAMPLE 1 Equal volumes of a Libyan high pour (+80F) gas oil and a midcontinent C light reformate were blended. properties of the two materials as follows:

The blend was processed over sulfided Ni/H/ZSM-S containing alumina binder at 500psig, 1.5 LHSV, 5000 SCF hydrogen/Bbl, 600F, for 14 hours. The product was fractionated to a naphtha cut point of 390F.

MA to 'ACC'JIQC uric-allot:

The R+0 and R+3 octane numbers of the C,,390F gasoline were 90.3 and 100.7, respectively (compared to 76.0 and 92.1 for the reformate charge), and the pour point of the 390F gas oil was F (compared to +F for the gas oil charge).

EXAMPLE 2 The Libyan gas oil set forth in Example I alone was passed over a fresh portion of the same catalyst used in Example 1 at 400 psig. 1.0 LHSV, 2,500 SCF hydrogen/bbl, 600F, for 27 hours. These conditions were chosen so as to produce a gas oil product having about the same pour product as the gas oil product in Example l. Yields follows:

C,+C ,wt. "/1 0.5 C wt. 71 7.9 (2 's. vo1.7r 21.5 C -,s. vol. '71 2.9 C ;390F gasoline, vol. /1 12.0 390F Gas oil, vol. 7: 58.8

The 390F+ gas oil again had a pour point of 75F, but the R+0 and R+3 octanes of the C 390F gasoline were about 80 and 93.8, respectively, much lower than the octane numbers in Example 1.

EXAMPLE 3 The midcontinent light reformate of Example 1 was contacted with the same catalyst at 600F, 3.7 LHSV, 5,000 SCF hydrogen/bbl, and 500 psig, sufficient conditions to produce a C 390F product having an octane number R+0 of 90.3. Yields as follows:

What is claimed is:

l. A process of upgrading petroleum fractions which comprises contacting an admixture ofa gasoline boiling range fraction having a boiling range of at least about C to 239F which contains at least about 20 weight percent aromatics and a gas oil fraction having an end point up to about 850F and a pour point of at least about +20F with a catalyst comprising a zeolite consisting essentially of a synthetic crystalline aluminosilicate zeolite derived in an organic cation containing form and having a silica to alumina ratio of at least about 12 to l; converting said admixture at a space velocity of about 0.5 to 20 WHSV and at a temperature of about 500 to l,0()0F to a product comprising a gas oil fraction having a lower pour point, a gasoline fraction having a higher octane and a light gas fraction; and resolving said product into said gas oil fraction, said gasoline fraction and said light gas fraction.

2. A process as claimed in claim 1 wherein said gasoline boiling range fraction is reformate.

3. A process as claimed in claim 1 wherein said gas oil fraction has an end point of about 850F.

4. A process as claimed in claim 1 wherein said gas oil fraction has a pour point of about 80 to F.

5. A process as claimed in claim 1 wherein said zeolite is in a porous matrix.

6. A process as claimed in claim 1 wherein said catalyst comprises an HZSM-5 zeolite and said process is 5 6 operated under a hydrogen atmosphere at a hydrogen 8. A process as claimed in claim 7 wherein said adto hydrocarbon ratio of about 1 to 20 to l and at a total mixture is a virgin petroleum fraction. pressure of about 1 to 70 atmospheres. 9. A process as claimed in claim 2 wherein said gas '7. A process as claimed in claim 1 wherein said adoil is a virgin petroleum fraction having a boiling range mixture is a wide cut petroleum fraction having a boil- 5 up to about 850F.

ing range in the range of about C to 850F.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3, 9 ,939 DATED July 15, 1975 INVENTOM 1 WILLIAM E. GARWOOD and JOHN J. WISE It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 66 L22" should be t i2-- Signed and Scaled this thirte Day of January 1976 [SEAL] Arrest.-

C. MARSHALL DANN Commissioner nfPatenls and Trademarks RUTH C. MASON Arresting Officer 

1. A PROCESS OF UPGRADING PETROLEUM FRACTIONS WHICH COMPRISES CONTACTING AN ADMIXTURE OF A GASOLINE BOILING RANGE FRACTION HAVING A BOILING RANGE OF AT LEAST ABOUT C6 TO 239*F WHICH CONTAINS AT LEAST ABOUT 20 WEIGHT PERCENT AROMATICS AND A GAS OIL FRACTION HAVING AN END POINT UP TO ABOUT 850*F AND A POUR POINT OF AT LEAST ABOUT +20*F WITH A CATALYST COMPRISING A ZEOLITE CONSISTING ESSENTIALLY OF A SYNTHETIC CRYSTALLINE ALUMINOSILICATE ZEOLITE DERIVED IN AN ORGANIC CATION CONTAINING FORM AND HAVING A SILICA TO ALUMINA RATIO OF AT LEAST ABOUT 12 TO 1, CONVERTING SAID ADMIXTURE AT A SPACE VELOCITY OF ABOUT 0.5 TO 20 WHSV AND AT A TEMPERATURE OF ABOUT 500* TO 1,000*F TO A PRODUCT COMPRISING A GAS OIL FRACTION HAVING A LOWER POUR POINT, A GASOLINE FRACTION HAVING A HIGHER OCTANE AND A LIGHT GAS FRACTION, AND RESOLVING SAID PRODUCT INTO SAID GAS OIL FRACTION, SAID GASOLINE FRACTION AND SAID LIGHT GAS FRACTION.
 2. A process as claimed in claim 1 wherein said gasoline boiling range fraction is reformate.
 3. A process as claimed in claim 1 wherein said gas oil fraction has an end point of about 850*F.
 4. A process as claimed in claim 1 wherein said gas oil fraction has a pour point of about 80* to 100*F.
 5. A process as claimed in claim 1 wherein said zeolite is in a porous matrix.
 6. A process as claimed in claim 1 wherein said catalyst comprises an HZSM-5 zeolite and said process is operated under a hydrogen atmosphere at a hydrogen to hydrocarbon ratio of about 1 to 20 to 1 and at a total pressure of about 1 to 70 atmospheres.
 7. A process as claimed in claim 1 wherein said admixture is a wide cut petroleum fraction having a boiling range in the range of about C5 to 850*F.
 8. A process as claimed in claim 7 wherein said admixture is a virgin petroleum fraction.
 9. A process as claimed in claim 2 wherein said gas oil is a virgin petroleum fraction having a boiling range up to about 850*F. 